280644 has 48 divisors (see below), whose sum is σ = 809088. Its totient is φ = 73728.

The previous prime is 280639. The next prime is 280673. The reversal of 280644 is 446082.

280644 is nontrivially palindromic in base 16.

It is a super-2 number, since 2×280644² = 157522109472, which contains 22 as substring.

It is a d-powerful number, because it can be written as 2⁷ + 8³ + 6⁷ + 0 + 4 + 4³ .

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 280644.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 964 + ... + 1220.

It is an arithmetic number, because the mean of its divisors is an integer number (16856).

2²⁸⁰⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 280644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (404544).

280644 is an abundant number, since it is smaller than the sum of its proper divisors (528444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

280644 is a wasteful number, since it uses less digits than its factorization.

280644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284 (or 282 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 280644 is about 529.7584355157. The cubic root of 280644 is about 65.4714441497.

It can be divided in two parts, 2806 and 44, that added together give a triangular number (2850 = T₇₅).

The spelling of 280644 in words is "two hundred eighty thousand, six hundred forty-four".